Making a Dirt Dog, Vol. 2: A N00b Goes Mountain Bike Shopping

Dylan Renn talks bikes. Photo: Jim Merithew/Wired

Peter and his Yeti in the hills of Marin County. Photo: Jim Merithew/Wired

Editor’s note: For those of you joining us late, Peter Rubin’s a roadie making his first foray into mountain biking. He knows nothing – seriously, zero – about that side of cycling, so he’s chronicling his adventures in the hope that others might learn from his inevitable mistakes.

So now I have my bike. Well, a bike. I’ve been out on the trail a few times, and I’m having fun. The problem now is that I don’t really know what I’m doing — and I mean that in two ways.

The first is a question of technique. Sure, I understand the fundamentals – how to distribute my weight in corners and during ascents or descents – but there’s more. A lot more. Handling hairpin turns, riding through berms, clearing obstacles, and generally being ready for whatever a trail might throw at me. Learning that comes from hours of riding, but I’m going to try to supplement that slow-burn skills acquisition by heading to a skills camp soon. Coaching outfit Better Ride gives one- and three-day clinics and camps all over the country, so I’ll catch up with them when they come to the Bay Area early next month.

Beyond the skills, though, there’s the gear. Oh, the gear.

The world of mountain biking gear is somehow even more daunting than that of road cycling. With a road bike, you buy in at a level you can afford. There may be slight differences in frame geometry that work better with your body type – long arms but short legs, long legs but short arms, general discomfort with twitchy handling and so forth. But generally speaking, there’s one kind of road bike.

Mountain bikes, though, can fall into multiple categories, each with its own strengths and tradeoffs. Because the vast majority of MTBs use some degree of suspension, you’re upping the number of moving parts and thus the number of choices you have to make. With that in mind, I headed up to 3 Ring Cycles in Marin County to see Dylan Renn. Renn’s a Better Ride coach, so I’ll see him at camp, but he’s also a veteran mountain biker who grew up riding granite in the Sierra Nevada mountains. He agreed to talk me through the MTB shopping process – a noob’s guide to buying a mountain bike, if you will. (Which means this is going to be rudimentary to many riders, so be patient.)

The great wheel-size debate: 26 or 29?

Traditionally, mountain bikes had 26-inch wheels (well, adult mountain bikes did). But starting in the ’90s, road-bike-sized wheels started to gain traction (zing!) among MTBers, and by now they’ve achieved near-parity in the marketplace.

Reasons to go with a 29: Bigger wheels equals easier to roll over obstacles. Slower to accelerate off the line, but more momentum once speed is reached. More rubber on the ground leads to slightly better traction and control.

Reasons to go with a 26er: quicker acceleration. You can muscle the bike around more easily, which feels familiar to BMXers. Might be better for smaller riders.

That’s it, right? Not exactly. To complicate matters, 650b wheels are growing more popular. They come out to about 27.5 inches in diameter (tire edge to tire edge), and in many people’s thinking represent the perfect medium: the acceleration and agility of a 26er with the stability and smooth roll of a 29er. 650b wheels also allow more travel in the front fork than 29-inchers do, which is good news for more aggressive racers. It’s still early in the evolution of the size, but more fork manufacturers are releasing 650b-compatible products.

Hardtail vs. dual suspension: How much spring do I need?

If you have the money, Renn says, go dual. Buying a hardtail certainly lets you get more bike for the money, since you’re not spending on an expensive rear-suspension system, but the traditional complaints about dual-suspension bikes – they climb poorly – are all but negated in higher-end bikes. Additionally, dual suspensions absorb the jarring that would otherwise be processed by your body, so you can ride longer without fatigue (or pain). Of course, we’re talking about stuff over $3,000, so let your budget be your guide. One more vote for a hardtail, though: For beginning riders, skills like wheelies, manuals (maintaining a wheelie without pedaling), and bunny hops may be easier to learn on a hardtail.

But aren’t dual-suspensions a lot of maintenance?

High-end forks are super-adjustable, and most average riders aren’t going to notice much difference among the various settings – but they also have a lot of what Renn calls “sealed internals,” so they’re going to require a lot of maintenance to maintain the proper pressure, etc. For a dual as a whole, though, Dylan says that it’s largely a matter of doing bolt checks every other ride to make sure everything’s tight. (And, as with any other bike, clean it as soon as you can after a ride, with a sponge or just blowing the dust off. If you get the thing muddy, it’s okay to use a hose, but make sure it’s not a high-pressure hose, and always direct the water from above, so you don’t blow water into the bottom bracket, where the bearing/grease equilibrium is so important.)

What are the various MTB types, and what do they do?

XC/Cross Country: Want to ride all day? Get an XC. The front fork has less travel – only 90-120mm of suspension – which means it’s not that plush a ride, and so is best suited to trails that aren’t highly technical with lots of roots, rocks, drops, etc. It’s also the stiffest and lightest category of mountain bike, with the most aggressive geometry. But why?

A bike’s “rake,” or fork offset, refers how far the center of the front wheel is from the bike’s head tube. The higher the rake, the farther from vertical (90 degrees) it is and the farther out the front wheel looks to be. A chopper-style Harley? Super-high rake. Rake is generally tied to a bike’s “trail” – the distance from where the steering tube would intersect with the ground to where the front wheel actually makes contact with the ground. Like so:

The more trail a bike has, the more stable it is, which makes it easier to ride with no hands and easier to handle steep descents. An XC bike doesn’t have that much of it. The handling will be the twitchiest of any MTB, but if you want to go fast through tight turns, and you’re not going to be heading off drops or through super aggressive terrain, this is your bet.

Trail: Not to be confused with a bike’s trail, or the trail you actually ride on. I know, I know. Trail bikes have a bit more travel than an XC bike – typically around 130-150mm – and a relaxed enough geometry that it can handle more aggressive riding while still staying light. Dylan also points out the longer-travel trail bikes are hitting the market that are still light enough for long rides and nimble enough for tight-radius turns, but let you hit rougher terrain.

All Mountain: Now we’re getting beefier. The Yeti SB66-C that I’m riding is an all-mountain bike, and is clearly built to handle anything a non-downhill rider needs. Renn describes an all-mountain rider as “someone who rides to the top, but doesn’t care how fast.” All-mountain bikes can climb, descend, handle, and muscle. All-mountain bikes are significantly heavier than XC bikes, but reward you with stability (the head angle is slacker than a trail bike), plushness (150-160mm of travel) and general all-around bulletproofness.

Downhill: Heavy as hell and built to drop. We’re talking up to 10 inches of travel and a suspension that can handle just about anything. Of course, you’re not going to be pedaling uphill anytime soon, but if you’re the type to take a shuttle or ski lift just to get to the start of your ride, this is your choice, you lazy-ass.

Renn didn’t hesitate: “If you live around aggressive terrain, then a trail bike. An XC otherwise. If you’re not racing, then a long-travel 29er with 130mm or so.”

So when it comes time for me to buy a bike, will I stick with an all-mountain like my Yeti? It’s too early to tell – I don’t know if I’ll gravitate toward XC riding or burlier stuff. But I do know this: as long as it can climb as well as the Yeti did riding in Marin County after I left 3 Ring Cycles, I’m sold.